It had been years since the Bills took McGahee with the 23d pick in the 2003 draft - a selection they made despite the knee injury that McGahee had sustained in the Fiesta Bowl that year, the hideous kind that no one forgets and few people recover from.

Studesville was McGahee’s first position coach, and with him, McGahee rang up two 1,000-yard seasons in three years with the Bills.

But last summer, with McGahee staring down the barrel of his 30th birthday, and his days as a feature back seemingly behind him, Studesville told Broncos head coach John Fox that he thought McGahee had some good football left in him.

Fox didn’t need to be sold.

“There definitely was some background there, and that was influential in us deciding to bring Willis in,’’ Fox said. “We don’t bring players in that we don’t think have football left. We felt very good about bringing him in here.’’

The Broncos signed McGahee to a four-year, $9.5 million deal. Not only did they have the league’s best rushing attack, but the 2,632 yards they gained were the most in franchise history.

McGahee was at the center of it, winning the starting job when Knowshon Moreno went down. He totaled 1,199 yards on 249 carries, his best season since 2007, when he was in his first year with the Ravens.

“Now they know,’’ McGahee said. “They’re not sleeping on me, I can tell you that much. I’m basically seeing eight, nine [defenders] in the box, so for somebody who don’t got it no more, that says a lot.’’

…

There was a point when it looked as though McGahee’s career was over. Actually, there has been more than one such point.

Anyone who saw the hit he took when he was playing for Miami in the 2003 Fiesta Bowl doesn’t need YouTube to see it again. It was the kind of unwatchable, gnarly image that’s impossible to forget.

Screen right.

One step, two steps, three steps, four, five.

Crash.

The helmet of Ohio State’s Will Allen took out McGahee’s left leg. His ACL, MCL, and PCL were torn.

McGahee was still a first-round pick in the 2003 draft, though he didn’t make his NFL debut until 2004.

It defied logic, but Fox, who was coaching the Panthers at the time, said no part of him was skeptical about McGahee’s potential.

“Not at all,’’ he said. “I think everybody in the league [was confident]. Willis coming out, he was a tremendous player.’’

In three seasons with the Bills, he ran the ball relentlessly (868 carries) and productively (3,365 yards), but eventually his welcome wore out. There was bitterness over comments he made in a Penthouse interview - a suggestion that the Bills move to Toronto - and by the time the Bills traded him to the Ravens for draft picks in 2007, he was essentially a dartboard in Buffalo.

In his first season in Baltimore, he piled up 294 carries and 1,207 yards, but that’s as good as it got.

He was there three more seasons, and his carries dipped each year, down to 100 last season. There were coaching changes (McGahee’s relationship with John Harbaugh was strained), and there was also a new young back in Ray Rice.

When he became a free agent last summer, Denver seemed like a fresh start.

Looking at his numbers, he said, the only difference between this season and last is opportunity. For a player used to carrying the ball 20 times a game, he was eager.

“I think it’s fairly obviously he was,’’ Fox said.

He has been the primary ball carrier, but for a core of younger backs, he also has been a veteran presence.

“He’s just been a leader,’’ said third-year back Lance Ball. “Last year we lost [Correll] Buckhalter, and we were looking for an older leader and they brought Willis in and he’s been great. Willis gives us pointers about running the ball.

“Willis isn’t really a talk guy, he’s all about action. He goes out there and he proves it on the field and we just follow.’’

For a quarter, anyway, the Broncos’ rushing attack dealt body blows to the Patriots in their regular-season meeting. They gobbled up 167 yards in the first quarter. McGahee ran for 70 of them.

Then a hamstring injury bit him. He spent most of the remainder of the game stretched out on the sideline, watching Tom Brady dismantle his team.

“I got hurt, and I didn’t finish the game,’’ McGahee said. “That’s one thing that sticks with me. It’s always difficult when you’re not on the field, regardless of the situation, win or lose. I wasn’t on the field at the end, so it’s always difficult.’’

The Broncos intend to give the Patriots heavy doses of McGahee tomorrow night, knowing how much the game changed when he went down in the first meeting.

“Obviously, he’s our workhorse in the backfield,’’ said offensive coordinator Mike McCoy. “We’re going to give Willis the ball 20-something times a game. That’s what we’ve been doing, give or take a few snaps here and there.

“When you lose your workhorse in the backfield, things change, but we have a system in place. Lance Ball has done a phenomenal job all year long. When Willis comes out, we just let him roll. Jeremiah [Johnson] has done a nice job coming in from time to time in the limited role that he’s had.’’

The Broncos ran for 131 yards against the Steelers last week. McGahee was held to just 61 on 19 carries, and he feels the Patriots will take pages from Pittsburgh’s book.

“I think they are going to try to stop us running the ball, because we are going to run the ball regardless of the situation,’’ McGahee said. “That’s what we need to expect, and they’re going to do everything in their power. I’m sure they watched some of the Pittsburgh film, and they are going to try to do some of those things.’’

But at this stage of his career, McGahee welcomes the workload.

“The season’s been good to me,’’ he said. “I’ve been having fun with it. It’s plenty more to come. It’s just a matter of us going out there and doing what we do best, and that’s make plays.’’